Power Section Test Voltages - No Load

This is where amp building starts to get dangerous. The Voltages/Amps are at lethal levels.

These voltages will be different once the Output Transformer and the rest of the amp is tied to it. These tests will show that the section is wired
correctly and the Power Transformer and Rectifier are converting voltages properly.

No tubes, No OT, and No need to have a speaker attached at this point.

Using a variac, the voltage was brought slowly up to line levels. In this case, a reference value of 117VAC. A variac is not required.
Many an amp has been build by holding your breath and flipping the on switch. This is the kinder gentler way however.

Once you are done powering this section, bleed your resistors and double check the turrets to be at 0 Volts before reaching in there again.


Line Power to Fuse 1 - Lamp on.

Fuse 1

Power Swith On: AC @ Lamp and Heaters

Lamp & Heat

AC In at Each Turret

ACIN Turret

DC Voltage after Rectifier, This voltage should be present at standby switch through Fuse 2.

AC IN Turret

AC Bias In Voltage

Bias In VAC

Take the Amp out of Standby: You will now have DC Voltage at B+ and Choke In. This is a No Load Voltage.

Pin 6 Voltage

The 10K resistor will drop the voltage from the choke a touch.

B+ No Load
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